Trying to set up third display on HP Lenovo Thinkpad E531 Edge?

I'm trying to set up my third monitor (laptop screen and two Dell monitors.) I really don't need the laptop screen I'm just using it as my "computer" so that I don't have to go out and buy a whole new computer tower. Obviously my knowledge of computers is less than nothing so I'm looking for help as to why my third monitor is being detected in the settings display menu but I can't get it to activate. It just stays greyed out and nothing I do will change that. As far is the setup of my connections goes on my laptop I have one VGA outlet that I'm using with the one monitor that is working and I'm also using a HDMI to VGA converter for the other (the monitor that is not working.) When I unplug the monitor from the VGA outlet the one that is connected via the HDMI converter pops on which leads me to believe that maybe my graphics card can't support 3 monitors. The graphics card is the following:

Thank you!

Added (1). The graphics card is:
Name: Intel(R) HD Graphics 4000
Chip Type: Intel(R) HD Graphics Family

Thomas

Your laptop has two output ports for video, and an internal screen. But the graphics device (part of the CPU chip, whatever that is) can support only two.
You can disable the laptop screen and use the two monitors through the two ports. The HDMI to VGA converter should work fine. If not, you can get an inexpensive USB to VGA external video device adapter. If you get it, then you can have three screens.

Starrysky